Why is the altitude shown on my watch incorrect? How do I calibrate the altitude on my watch?

The altitude on an altimeter watch is based on atmospheric pressure. This means it is sensitive to changes in weather, so you'll need to calibrate your device regularly.

To do so, proceed as follows:

Starting from the "time" screen, press the MODE button (bottom left)

Once in ALTI mode (altitude is displayed), hold the SETTINGS button (top left) down for 3 seconds

The altitude will start flashing

Adjust to the altitude of your current location (obtained from map or elevation marker) by pressing the buttons on the top right (+) or top left (-) 5. Once you've set the altitude, exit the menu by pressing the SETTINGS button (top left)